The Dexcom G4 is a continuous glucose monitoring system (CGMS) worn by type 1 diabetics. It has a USB port and Windows only software for downloading and analysing data.<p>A team of developers / users have created an open source realtime remote monitoring, alarm and glucose prediction system for it. It uses a USB OTG cable to connect the Dexcom to a commodity Android phone, which runs a custom Android app to upload the data to MongoLab. From there, a Node.js powered dashboard gives viewers - typically parents of diabetic children - a way to monitor glucose levels remotely. In addition, a Pebble watch app lets the wearer check their glucose by just looking at their wrist, instead of having to use the bulky Dexcom monitor.<p><a href="http://nightscout.github.io/posts/01-quickstart/" rel="nofollow">http://nightscout.github.io/posts/01-quickstart/</a>
I had a teacher make seating charts in Bingo Card Creator by exploiting the fact that, for the free trial, the random perturbation of the words is deterministic. She put 1 through 25 in the word list, observed where they showed up on the bingo card, then replaced them with students' names to get the desired seating chart. (How do I know this? Because she bought BCC and that replaced the deterministic random seed with an actual random seed, causing the seating chart to break and her to send me a support email the next time she tried printing it.)<p>Given that one of my Internet buddies runs a table planning software company I probably should have bought her a license on general principles.
When I did phone support for a barcode scanning company I had one customer trying to use an undecoded scan engine to guide robots across a floor.<p>A scan engine works by sweeping a laser across the barcode and using the light intensity at different points to determine where the bars and spaces are relative to each other. A modern scan engine will usually output what data was in the barcode, but an undecoded scan engine outputs a continuous stream of data indicating the light intensity received from the laser.<p>If I recall correctly, they had a bunch of timing marks on the floor that the robot would follow, and they were scanning these using the engine. You could keep a robot on-track in this way because, if the laser is angled relative to the timing marks a large part of the sweep isn't going to contain any marks and so the robot needs to correct. Then it's just a matter of servo'ing down the line.<p>I would never have thought to do something like that so it was probably the best call I'd gotten all year.
Shortly after launching Cronitor.io, (a dead-simple SaaS solution for monitoring cron jobs), we noticed a large number of tracking events coming from a specific user -- 3000x more than we normally see after a user starts monitoring a job.<p>The normal use case is to curl your tracking URL at the end of your crontab line, so seeing 25k events coming in over 48 hours clued us in that Cronitor was being used for something different than we expected.<p>Turns out, the user needed to do a big one-time batch processing of thousands of records and wanted to keep track of how many were done, and wanted to be alerted when the process was complete. By curling his tracking URL at the end of his event loop, he could leave behind his workstation and trust that he would be notified when the batch was done.<p>(If you want to know a little more about Cronitor, check out an awesome blog post from my co-founder, The First Paying Customer <a href="https://news.ycombinator.com/item?id=8020980" rel="nofollow">https://news.ycombinator.com/item?id=8020980</a>)
As William Gibson put it: "The street finds it's own uses for things."<p>Back before cell phones, Motorola sold a lot of walkie-talkie type radios. Most of these were 'ruggedized' (encased in big thick yellow/orange rubber padded boot). One day, Motorola engineers came up with a 'better' padded boot they thought would help the radios survive a fall.<p>But they got complaints from the Air Force. So they investigated..<p>It turns out that the Air Force mechanics need to 'chalk' their airplanes to track state (bombs loaded, fuel loaded, etc). But the mechanics were always loosing their chalk. So they would just 'scrape' the plane with the (padded) back of their radios, and it would leave a (non-permanent) mark like chalk. The 'improved' padding didn't work the same way, so they asked Motorola to keep selling the old padding (and they did).<p>(Heard this a long time ago. Really fuzzy on all the details, but I'm sure it's true.)
I sold surveillance cameras when I was in University and had a customer build something similar to a GoPro using a bullet camera, a portable mini-dvr and battery packs. I don't recall the quality being very good, but he was an interesting guy!
While any specific use isn't very interesting, an honorable mention should go to the army's P-38 can opener. It was the minimum amount of sheet metal wrapped around just barely enough of a cutting surface to open a can of C rations.<p>As they were cheap and easily available due to being standard in a pack of rations, they ended up being used for... everything. The link below mentions a few of the simple can opener ended up being used, if you want a few examples and has a picture of the tool.<p><a href="http://olive-drab.com/od_rations_p38.php" rel="nofollow">http://olive-drab.com/od_rations_p38.php</a>
I write software used by organizations that help individuals with developmental disabilities. Sometimes the organizations have to babysit the individuals (day programs), or have them help with work, while their guardians are out working during the day.<p>I recently got a call from a staff at an org that was having an individual help with her workload by using our software - she was honestly complaining that an update we had pushed out had made things so much more efficient, so that the individual they were babysitting/keeping busy/working finished their work so much faster that they didn't know what else to do with her. She wanted us to revert our update back to a state of being less efficient. (Of course we responded that we can't support that type of organizational workflow...)<p>We had no idea our system was used as a tool for keeping people busy for the sake of being busy and not causing trouble!
A company I occasionally do support for has a profitable legacy system that runs on 486 or lower PCs. Supplier of product out of busiess. One PC died and they couldn't get any more. I found a manufacturer of current PC104 boards with a 486 CPU. moved the software across to those. It nearly worked but would occasionally crash. I asked a genius friend to have a look at it. He got out his trusty DOS debug floppy disks, footled around for a few days working out what was wrong (slightly incompatible implementation of serial port in the SoC on the PC104 boards, plus crap code in the original system), hand-assembled a workaround and wrote it in to blank space on the original executable, and presto! the system has been running reliably on the new hardware for a couple of years now.
It's not software, but it's really awesome.<p><a href="http://www.ikeahackers.net/" rel="nofollow">http://www.ikeahackers.net/</a><p>Hacking cheap furniture. Ikea actually gave them some grief for a time, but I think they backed off.
"Show HN" was organic, now 'official', and one of this site's best features.<p><a href="https://news.ycombinator.com/show" rel="nofollow">https://news.ycombinator.com/show</a>
A friend's family owns a plastic manufacturing facility. They buy a lot of Coca Cola, for cleaning their manufacturing equipment (of grease, oil etc) after each production round. Much cheaper than the industrial cleaning agents.
I definitely recommend exploring the Sugru site (<a href="http://sugru.com/" rel="nofollow">http://sugru.com/</a>) - it's a product basically made for clever product hacks by customers.